Simmons II Flashcards
1
Q
Where does THF come from?
A
B9
2
Q
What does THF do?
A
Important cofactor in biosynthesis of purines and thymidylate
3
Q
Form of THF in purine synthesis?
A
N10
4
Q
Form of THF in pyrimidine synthesis?
A
N5N10
5
Q
What is Megaloblastic anemia?
A
- Result of folate deficiency in which blast cells are unable to replicate DNA and divide
- They just keep on getting bigger leading to weak membrane and poor O capacity
6
Q
What are blast cells?
A
Premature RBC with no nucleus
7
Q
What does 5-methyl-THF do?
A
- Converts homocysteine to methionine
- Homocysteine is toxic and methionine is used in AA metabolism
- This is the only reaction 5-methyl-THF is used in and the reaction converts it back to THF
- B12 required for reaction
8
Q
What reaction requires B12?
A
homocysteine to methionine necessary for AA metabolism
9
Q
What deficiency does b12 deficiency cause?
A
Folate
10
Q
What are the purine bases?
A
Adenine
Guanine
2 ring structure
11
Q
Nucleotide/side difference?
A
Nucleotide is side with added phosphate
12
Q
Three pyrimidines
A
Cytosine, uracil, and thiamin
13
Q
What does purine synthesis start with?
A
5 ribose phosphate
14
Q
Branchpoint in purine synthesis?
A
IMP - can become amp or gmp
15
Q
What is required for purine synthesis?
A
THF, AAs, Co2
